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Here are the Signs of Childhood Cancer—From a Doctor Who Survived It

A patient-turned-expert reveals the warning symptoms every parent should know.

For pediatric oncologist Colin Moore, MD, September's Childhood Cancer Awareness Month has a double resonance. Today, he treats children with cancer, particularly cancers of the blood. Twenty-two years ago, he was a childhood cancer patient himself.

As a med school student, Moore initially wanted to stay far away from oncology. But when he observed the pediatric cancer department, "I saw a little bit of myself in each one of the patients," says Moore, 38, who practices at Johns Hopkins All Children's Hospital in St. Petersburg, Florida. "And even more importantly, I saw a lot of my parents in every single parent I spoke with."

Childhood cancer is rare: In the United States, just under 16,000 children are diagnosed with cancer every year. But every parent worries about it and wants to know which symptoms to watch for.

Making those recommendations is tricky. First, because—and this bears repeating—childhood cancer is rare. Second, symptoms of cancer are usually vague—a stomachache or headache is most likely not cancer.

Colin Moore, M.D., on the day of his diagnosis.Provided

At age 16, Moore noticed swelling in his leg and began having migraine headaches. After experiencing double vision, he "finally broke down" and asked his parents to take him to the doctor. After three months of exams and tests, doctors connected the dots between his symptoms and diagnosed Ewing's sarcoma, a soft-tissue cancer that originated in his leg and had spread to his brain.

Surgeries, radiation, high-dose chemotherapy and a bone-marrow transplant followed. Today, Moore is cancer free. He says the key to catching childhood cancer early is to be aware of symptoms that linger, or a constellation of physical signs, like he had; they might signify a larger issue.

But he emphasizes that no two cancers are exactly alike.

"One of the toughest things with childhood cancer is that most of the cancers we see don't just have one symptom that pops out at somebody," says Moore. "Most of the symptoms mimic other illnesses. The biggest thing we teach is that common things are common. If you have a fever, that's probably a cold. But when symptoms don't go away or don't have a simple answer, it's time to give the pediatrician a call and ask, 'Is this normal'?"

These are some of the most common signs of childhood cancer. (Although the list is by no means complete. The golden rule is, when something doesn't seem right, ask your pediatrician.)

Unexplained Weight Loss

Feet on scales on wooden floor

"The main thing we see is unexpected weight loss," says Moore. "Especially in the adolescent age—you have a little bit less oversight of what your kids are doing and how they're growing, you're going to the pediatrician's office less." A common early sign of cancer in adults as well as children, unexplained weight loss happens because cancerous cells can hijack the body's metabolism, appropriating calories for their growth at the expense of muscle and bone.

Not Gaining Weight or Delayed Crawling

pediatrician doing abdominal examination

Because childhood cancer can have non-specific symptoms and grow quickly, it's especially important to keep every recommended pediatrician's appointment, says Alex Ota, a public relations executive in San Clemente, California. A decade ago, her infant daughter was diagnosed with neuroblastoma, the most common infant cancer, at her nine-month checkup. "She was eating voraciously but had only gained 3 ounces," says Ota, who had noticed that her daughter hated "tummy time." "This was a red flag to the doctor. She also hadn't started crawling yet. When the doctor palpated her stomach—something my pediatrician always does at check-ups, and now I know why—he clearly felt the tumor."

"She was eating voraciously but had only gained 3 ounces."

After surgery to remove a large mass, then recurrence and a second surgery, Ota's daughter is a healthy ten year old today. "My pediatrician kept stressing how important the 9 month check up is," says Ota. "Many parents skip it because their baby was checked at 6 months. If we would've skipped it, we may not have the outcome that we did — today's healthy daughter."

Change In A Mole Or Freckle

Female Doctor Examining Skin Of Little Boy With Dermatoscope

Melanoma, the deadliest form of skin cancer, is considered an adult disease — the consequence of too many hours and seasons spent in the sun. But it's also the second most frequently diagnosed cancer in adolescents and young adults aged 15 to 29, says Keira Barr, MD, a dermatologist based in Gig Harbor, Washington.

Be aware of any changes in moles, freckles or spots on your child's skin. Teach them to do the same. A mnemonic device could help: "Look for the ugly duckling," says Barr, who diagnosed her own melanoma seven years ago. "Getting to know your skin well and looking for the typical pattern that your moles and freckles follow is key. A spot that stands out from the crowd is the ugly duckling and warrants evaluation by your dermatologist."

Barr also recommends "following the ABCDE's:"

  • A = Asymmetry. "If the spot is asymmetrical, uneven or lopsided looking, get it checked out," says Barr. "Typically, moles and freckles are symmetric circles or ovals."
  • B = Border. "If the spot has a jagged, poorly defined or irregular border, it should raise suspicion," says Barr.
  • C = Color. "If the spot has a variable color or several different colors, get it checked," says Barr. "Typically moles are evenly pigmented throughout."
  • D = Diameter. "If the spot is larger than 4 to 6 millimeters in diameter — about the size of a pencil eraser — it could be a cancer, though there is a broad range of variability, and this is the weakest sign for a suspicious spot," says Barr.
  • E = Evolving. "If the spot is growing, changing or evolving over time, get it checked out," says Barr. "Typically moles, freckles, and birthmarks remain constant in their appearance over time."

Chronic Pain

a little girl in her bed has a stomachache

"Parents need to talk to their kids if something is hurting, and let their children know to always tell them if something isn't right," says Ota. In the hospital where her daughter was being treated, she met the family of an adolescent boy who had been afraid to tell his parents about a constant pain in his groin. It was ultimately diagnosed as testicular cancer; by the time they sought medical treatment, the disease was advanced.

"I remember his dad crying as he told me his son was too embarrassed to speak up," says Ota. "If your kids tell you something doesn't feel right, don't brush it off. Take an honest look at it. You don't want to be a doomsdayer, but you also don't want to shrug away important signs."

Persistent Unexplained Cough And/or Swollen Lymph Nodes

girl feeling unwell and coughing

"This is a common finding in children with non-Hodgkin's lymphoma," says Anthony Kouri, MD, an orthopedic surgeon at the University of Toledo Medical Center. "The cough is due to a mass in the chest cavity. These children may also have swollen lymph nodes in the axilla [armpit] and above the clavicle. Any of these symptoms should be red flags to a health professional. These lymph nodes should be biopsied, and a CT or MRI may need to be performed."

Easy Bruising or Bleeding, or Frequent Nosebleeds

mother bandaging her child elbow

According to the American Cancer Society, leukemias are the most common childhood cancer, accounting for one out of three childhood cancer diagnoses. Common signs include bruising easily, unusually large bruises, easy bleeding, or frequent nosebleeds. They can result from a lack of platelets, the cells that cause blood to clot which are often destroyed by leukemia.

Painless Abdominal Mass

Father And Son Having Fun Playing On Sofa Together

"A unilateral painless abdominal mass is a common sign for a Wilms tumor, or nephroblastoma, a type of kidney cancer that is the most common intra-abdominal tumor in children," says Kouri. "These can grow to be very large before they are noticed. Parents often notice the mass while lifting the child or giving them a bath."

Loss Of Appetite

Portrait of child with no appetite in front of the meal

Kids wouldn't be kids without being finicky eaters once in a while. But if your child has a persistent loss of appetite, it could be a sign of cancer in the spleen, liver, or lymph nodes, which could be pushing on the stomach and making him or her feel full sooner. It warrants a visit to the pediatrician.

Pain Not Relieved By Rest

The little boy is holding his knee, he feels strong knee pain

"It is not abnormal for kids to complain of some pain in their leg or knee while playing sports," says Kouri. "However, pain that isn't relieved by rest is a red flag. This may be an indication of a bone tumor such as an osteosarcoma. Other symptoms to watch out for include pain that's worse at night, limping, and a soft tissue mass. If a child is experiencing these symptoms, they should be referred to an orthopedic surgeon."

Increasing Head Size

Professional pediatrician examining smiling baby

"Infants and young children whose fontanels — or soft spots — have not closed yet may have no sign of a brain tumor except that their head is growing faster than it should," says Kouri. "This occurs because the head expands as the tumor grows. It's important to feel the fontanels and for the doctor to measure your child's head until they are two. The child may express discomfort and fussiness with head rolling. If the child is exhibiting these symptoms, a computed tomography (CT scan) or magnetic resonance imaging (MRI) should be performed."

Persistent Fever

Sick little girl covered in blanket is lying on couch

Fever is the body's natural sign of infection. A prolonged fever that doesn't seem related to a cold or flu could indicate a lack of white blood cells, the body's infection fighters. Their numbers can be reduced in some cancers, including leukemia.

Prolonged Fatigue

the boy rubs his eyes from fatigue

Recurrent fatigue can be a symptom of a number of childhood cancers. For example, in leukemia, a blood cancer, fatigue often results from anemia, a shortage of red blood cells. If your child is more low-energy than usual and can't seem to shake it off, talk to your pediatrician.

For Moore, he hopes Childhood Cancer Awareness Month will raise awareness not just of symptoms but of the need to fund effective treatments and cures. Childhood cancer tends to be overshadowed (and thus underfunded) by adult cancers. "Twenty-two years since I was diagnosed, we have made incredible leaps in treating certain cancers, like leukemias and certain solid tumors like neuroblastomas," he says. "But for the cancer I had, Ewing's sarcoma, the medications I received back in 1997 are the same drugs we use for treatment if a child walked through my door today."

"We need help," he says. "We need help on every single front to try and find a better cure."

Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael